How far the field of the Roman power went beyond the Roman towns and garrisons and the end of the imperial roads, we are not able to say. The broad steppe-land round the salt-lakes to the west of Lambaesis, the mountain-region from Tlemsen till towards Fez, including the coast of the Riff, the fine corn-country on the Atlantic Ocean southward from Sala as far as the high Atlas, the civilisation of which in the flourishing time of the Arabs vied with the Andalusian, lastly, the Atlas range in the south of Algeria and Morocco and its southern slopes, which afforded for pastoral people abundant provision in the alternation of mountain and steppe pastures, and developed the most luxuriant fertility in the numerous oases--all these regions remained essentially untouched by the Roman civilisation; but from this it does not follow that they were in the Roman time independent, and still less that they were not at least reckoned as belonging to the imperial domain. Tradition gives us but slight information in this respect. We have already mentioned (p. 313) that the proconsuls of Africa helped to make the Gaetulians--that is, the tribes in southern Algeria--subject to king Juba; and the latter constructed purple dyeworks at Madeira (p. 338, note). After the end of the Mauretanian dynasty and the introduction of the immediate Roman administration, Suetonius Paullinus crossed, as the first Roman general, the Atlas (p. 313), and carried his arms as far as the desert-river Ger, which still bears the same name, in the south-east of Morocco. His successor, Gnaeus Hosidius Geta, continued this enterprise, and emphatically defeated the leader of the Mauri Salabus. Subsequently several enterprising governors of the Mauretanian provinces traversed these remote regions, and the same holds true of the Numidian, under whose command, not under the Mauretanian, was placed the frontier-range stretching southward behind the province of Caesarea;[286] yet nothing is mentioned from later times of war-expeditions proper in the south of Mauretania or Numidia. The Romans can scarcely have taken over the empire of the Mauretanian kings in quite the same extent as these had possessed it; but yet the expeditions that were undertaken after the annexation of the country were probably not without lasting consequences. At least a portion of the Gaetulians submitted, as the auxiliary troops levied there prove, even to the regular conscription during the imperial period; and, if the native tribes in the south of the Roman provinces had given serious trouble to the Romans, the traces of it would not have been wholly wanting.[287] Probably the whole south as far as the great desert passed as imperial land,[288] and even the effective dependence extended far beyond the domain of Roman civilisation, which, it is true, does not exclude frequent levying of contributions and pillaging raids on the one side or the other. [Sidenote: Incursions of the Moors into Spain.]